The present disclosure relates generally to heat exchangers utilized in heating, ventilation, and air conditioning (HVAC) systems. Evaporators and condensers of an HVAC system generally utilize heat exchangers to control a temperature of an external fluid, such as air, passing over tubes of the heat exchangers. For example, each heat exchanger generally includes tubes for flowing refrigerant (e.g., R-410A, steam, or water) between headers that are connected to a refrigerant inlet and outlet. As refrigerant flows through the tubes, the refrigerant may exchange heat with air flowing over or between the tubes. The air may then be distributed to a commercial or residential space requiring temperature-controlled air.
In many HVAC systems, the refrigerant undergoes a phase change while flowing through (or to) the heat exchangers in which evaporation or condensation occur. Generally, a portion of the heat transfer is achieved from the phase change that occurs within and/or immediately adjacent the heat exchanger. That is, while some energy is transferred to and from the refrigerant by changes in the temperature of the fluid (i.e., sensible heat), other of the energy is exchanged by phase changes (i.e., latent heat). Thus, the heat exchanger (e.g., of the evaporator, of the condenser) generally handles two-phase flow (e.g., part liquid, part vapor). Efficiency of the evaporator is improved by improving homogeneity of the two-phase flow, and by equalizing distribution of the refrigerant to the tubes. Unfortunately, traditional HVAC heat exchanger (e.g., evaporator) configurations may regularly cause heterogeneous two-phase flow. Accordingly, improved heat exchangers are desired.